TableSine< Stap, Ts > Class Template Reference

Lookup table sine oscillator. More...

#include <Oscillator.h>

Inheritance diagram for TableSine< Stap, Ts >:

List of all members.

Public Member Functions
	TableSine (float frq=440, float phase=0)
float	operator() (float freqOffset=0)
	Return next linearly-interpolated sample.
float	nextN (float freqOffset=0)
	Return next non-interpolated sample.
float	nextL (float freqOffset=0)
	Return next linearly-interpolated sample.
void	freq (float v)
	Set frequency.
float	freq () const
	Get frequency.
void	phase (float v)
	Set phase from [0, 1) of one period.
float	phase () const
	Get phase in [0, 1)
void	phaseMax ()
	Set phase to maximum value.
void	phaseAdd (float v)
	Add value to phase [0, 1)
void	period (float v)
	Set period length.
void	reset ()
	Reset phase accumulator.
bool	done () const
	Returns true if tap is done.
uint32_t	freqI () const
	Get fixed-point frequency.
float	freqUnit () const
	Get frequency in [0, 1)
uint32_t	phaseI () const
	Get fixed-point phase.
uint32_t	cycle ()
	Returns 0x80000000 on phase wrap, 0 otherwise.
uint32_t	operator() ()
	Alias of cycle()
uint32_t	nextPhase ()
	Increment phase and return pre-incremented phase.
uint32_t	nextPhasePost ()
	Increment phase and return post-incremented phase.
uint32_t	cycles ()
	Get 1 to 0 transitions of all accumulator bits.
Static Public Member Functions
static void	resize (uint32_t bits)
	Resize global sine table.

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Detailed Description

template<class Stap = tap::Wrap, class Ts = Synced>
class gam::TableSine< Stap, Ts >

Lookup table sine oscillator.

This oscillator looks up values in a table containing the sine function in [0, pi/2]. Doing a non-interpolating table lookup is very fast and stable compared to other methods. The downsides are that the waveform is generally not as spectrally pure and additional memory needs to be allocated to store the lookup table (although it's relatively small and only allocated once).

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Constructor & Destructor Documentation

TableSine	(	float	frq = 440,
		float	phase = 0
	)

Parameters:

[in]	frq	Frequency
[in]	phase	Phase in [0, 1)

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Member Function Documentation

uint32_t cycle

(

)

[inherited]

Returns 0x80000000 on phase wrap, 0 otherwise.

The return value can be used as a bool. It's an integer because it saves a conditional check converting to a bool.

void resize

(

uint32_t

bits

)

[static]

Resize global sine table.

Parameters:

[in]

bits

set effective table size to be 2^bits

This sets the effective table size with only one quarter the amount of memory actually being allocated. For example, if bits=10, the effective table size is 2^10 = 1024, but the amount of allocated memory is only 1024/4 = 256. This call is not thread safe.

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The documentation for this class was generated from the following file:

• /Users/ljp/code/gamma/trunk/Gamma/Oscillator.h